NOTE: The DSM V made significant changes in the available diagnoses for those conditions considered to be 'on the spectrum'. Gone is the official diagnosis for PDD-NOS and Aspergers for example. Now it is all part of a spectrum. Here is a breakdown on what those changes are:

It should be noted that no one is saying that all of these symptoms that have, in the past, led to these diagnoses have mysteriously and miraculously gone away. Instead, it has been determined that these discrete categories are not going to be recognized. Instead, all of these symptoms will lead to a general Autism Spectrum Disorder diagnosis.

Here is brief video clip from Temple Grandin as she

traces the historical path of the autism diagnosis:

[I have included articles on PDD-NOS for historical reasons and because while the names and diagnoses have changed, the underlying symptoms have not.Accordingly, I believe that these sources continue to be of value]

What is PDD-NOS anyway?"Consider this - your child is at an 'ASD buffet' and takes a little of this and a little of that. There is a smorgasbord of symptoms. Confusing? Frustrating? Yes - here are some sites. This is good for a general understanding - from Autism Speaks - http://www.autismspeaks.org/navigating/pdd_nos.php